Expansion-pulley



(No Model.)

2 Sheets-Sheet 1. J. e. MERY. i

EXPANSION PULLBY. No. 443,561.

Patented Dec. 30, 1890.

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J. G. AVERY. EXPANSION PULLEY.

No. 443,561. lentented Dee. 30, 1890.

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UNITED STATES PATENT OEEICEC JOHN G. AVERY, OF SPENCER, MASSACHUSETTS.

EXPANSION-PuI LEY.r

SPECIFICATION forming part of Letters Patent No. 443,561, dated December 30, 1890.

Application filed April 23 1890. Serial No. 349,152 (No model.)

To all whom t may concern.'

Be it known that I, JOHN G. AVERY, a citizen of the United States, and a resident of Spencer, in the State of Massachusetts, have invented a new and useful Improvement in Expansion-Pulleys, of which the following is a specification.

This invention relates to the construction of expansion-pulleys and their accessories;

and it consists in certain novel combinations of parts hereinafter setforth and claimed. Its objects are, first, to give such pulleys a wide and practically unlimited scope of relative adgustment or change, so as to readily provide for increasing or decreasing the speed ofthe driven shaft relatively to that of the driving-shaft to any required extent; secondly, to provide for simultaneously opening one pulley and closing the other, so as to gradually change the speed by a simple mechanical device, and, thirdly, to effect such gradual change of speed automatically, with provision for readily varying the rate of change relativelyto the speed of the drivingshaft at will.

In connection with the provision lastnamed A and with suitable worm-gearing the improved expansion-pulleys are adapted to take the place of the lever-motion devices commonly employed in connection with pawl-and-ratchet converting mechanism in loom let-offs; but with or without such accessories the improved expansion-pulleys may be employed as machine clements in any kind of machinery where they can be utilized. v

Two sheets of drawings accompany this specification as part thereof.

Figures l and 2 of the drawings are diagrammatic elevations of a pair of the improved pulleys with their accessories as elnbodied in a loom let-0E, partly in section, showing the parts at or near the respective extremes of their movements. Fig. 3 is an elevation of a pulley detached and partly open; and Fig. 4 is a section on the line 4 4, Fig. 3.

Like letters of reference indicate corresponding parts in the several figures.

Each of the improved expansion-pulleys is constructed in the manner represented by Figs. 3 and 4, to which reference may first be 'had-that is to say, each pulley is composed of a hub 7L, adapted to be made fast upon a rotary shaft. by a radial screw s or the like; a hub h2, adapted to slide on the same shaft and for heavy work splined thereto, as dotted at s2, Fig. 2, and provided with a peripheral fork-groove g or the like; eight (or more or less) belt-carriages c, equally distributed in a central zone; two pairs of uniform leverarms ct l) a2 b2 in parallel pairs connecting each belt-carrier with both hubs, and suitable pivotal connections at the respective ends of each pair of lever-arms. 'lo forni such connections in a suitable way at the belt-carrier ends of the lever-arms, each belt-carrier c, being preferably of malleable iron or steel,is cast with a central web w, Figs. 3 and 4, which projects radially inward, and with end projections or lugs ce in the same plane, which extend radially outward, all of which are drilled to receive parallel bolts or rivets r', by which the adjoining ends of the lever arms are pivoted thereto. To form such pivotal connections at the hub ends of the lever-arms the inner end of each hub is made with flat peripheral surfaces in lin e longitudinally with the respective belt carriers, and suitable hinge-pieces or pivotal connections p, Figs. 3 and 4, are attached to said peripheral surfaces and constructed with lugs y .e in line longitudinally with said webs w and lugs 06 and likewise drilled to receive parallel bolts or rivets r r2, by which the corresponding ends of the lever-arms are pivoted therethrough to the hubs h and h2, respectively. Cast-iron hubs may thus be readily provided with suitable pivotal connections of malleable iron or steel or other more suitable metal. A pair of such expansion-pulleys P P2, Figs. l and 2, are mounted, respectively, on a driving-shaft S and a driven shaft S2 parallel therewith. The two pulleys are reversed end for end relatively to each other, and, having been arranged on the shafts with the belt-carriers of one in line with those of the other and with allowance for the movement ofthe sliding hubs in opposite directions the required distance, the fast hubs 7L are tightened on the respective shaft-s and a suitable driving belt B is stretched around the two pulleys on their belt-carriers c. The sliding hubs h2 may then be permanently engaged with the adjusting devices.

To provide forsimultancously opening and ICO . closing the respective pulleys their slidingr hubs 7iQ are engaged by a pair ot' forks j" at the respective ends ot a rigid eoupling-hart. and this is conveniently moved back and iorth by means ot a sliding bar h" parallel with the shafts S Si?, which works in lixed guides (Si and is rigidly jointed to said eoupling-bar, as atj.

ln the arrangement represented by Figs. 'l and 2 I further provide for automaticallyadjusting the pair oi pulleys so as to gradually increase or decrease the speed ot the driven shaft Si, and consequently that ot rotary motion transmitted therct'rom or controlled thereby, with provision for gradually and uni- Ati'ormly increasing or decreasing the rate of change, as aforesaid, and with provision also for readjustin g the pulleys by hand. To etlect these objects motion is transmitted trom said driven shaft Sithrou gh a worm\\,fast thereon, a worm-gearll'i, and a clutch C2 to a shaft S, which in turn, through a wormlY, fast thereon, and a wornrgearllv l, fast on a spindle S,drives or controls the rotation of the latter, and said spindle S, through a worm Wi, fast thereon, and a worm-gear "in mesh therewith, drives a micrometer-screw Si'. This screw reciprocates a traveling nut N, which is connected with said slide S by a slotted levcrl., engaging with studs on the nut and slide and having a movable fulcruinf. A movable arm A, to carry the fulcruni f, has a lined pivot p at its opposite end and a slotted sector s', through which a fastening-bolt b passes into the fixed frame-part l, to which the arm is pivoted. The driving-shaft S receives its motion through bevel-gearing.Gl, or it may bc more directly from the power-shaft S, and through the automatic adjusting devices above described a portion of the transmitted power is utilized to slowly and steadily open and close the respective exliansion-pulleys so as to change the speed according` to a predetermined rule with mechanical accuracy. 'Said shaft Si' is further provided with a handwheel Il, so that when it is unclutched from said wor1nwheel\\"" thereon the shaft may be turned by hand so as, through said worm XV" and worm-gear to turn the spindle S* either way, and through said spindle S, worm W", wornrgear lV, screw S, nut N, lever L, slide S', and eouplingba r (l to readj ust the pulleys l" Pi by hand. lo increase the scope or capacity for change oi' expansion-pulleys fitted to given shafts to Iany required extent, it is only necessary to make the pulleys with lever-arms of greater length. For greater strength the levenarms at each point maybe doubled or applied on both sides of the re spective pivotal lugs. In a loom let-oft said power-shaft S would be the main shaft oi' the loom, and said spindle S* the warp-beam spindle. The expansion-pulley l would be closed and the expansion-pulley P2 open, as in Fig. 1, at the beginning of the operation with the warp-beam full, their peripheral speed being then as one to threeA When the warp beam nearly empty, the parts appear as in Fig. with the peripheral speed oi the rclspcctive pulleys reversed or as three to one, and byshitting the fulcrum-arm A the rate of change is increased or diminished in reverse ratio tothe distance between the movable fnlcrumj'" and the pivotal stud on the nut N, so that the warp shall be let oft according to the desired number of picks to the inch.

Another intended application ot the im proved expansion-pulleys is to electric motors for vehicles, so as to provide for driving the axles slow, for maximum power, in starting and in climbing grades, and for graduallyin creasing thc rate of speed of the vehicle at will without changing the speed or power ot' the motor and without the employment of trains oi' spur-gearing.

Other applications thereof and additional modifications will suggest themselves to those skilled in the art.

Mechanical details which have not been specitied may be ot anyapproved description.

ll'aving thus described said improvement, I claim as my invention and desire to patent under this specilication-- 1. An expansion-pulley having lever-arms in parallel pairs connecting each belt-carrier with a hub adapted to be fastened on the shaft at one end of the pulley and with a huh adapted to slide on the shat't at the other end of the pulley, substantially as hercinbefore specified.

2. Apairot expansioirpulleys,each having a pairot hubs adapted, respectively, to be fastcned on its shaft and to slide thereon, a sutiicient number of belt-carriers equally distrib uted in a central zone, and lever-arms in parallel pairs connecting each belt-carrier with the respective hubs, the sliding hubs being at the opposite ends ot' the respective pulleys,in combination with a rigid coupling-bar connecting said sliding hubs,aslide parallel with the respective shafts and rigidly jointed to said bar, a belt connecting the pulleys, and a driving-shaft and a driven shaft 0n which the respective pulleys are mounted, substantially as hereinbeforc specified.

3. The combination of a driving-shalt and a driven shaft parallel with eachotl1er,apair of expansion-pulleys mounted on said shafts and cach having a fast hub and a sliding hub, a belt connecting said pulleys, a coupling-bar connecting their sliding hubs, a traveling screw-nut connected with said bar, a rotary screw to actuate said nut, and mechanism transmitting motion lfront said driven shaft to said screw, substantiallyas herei nbetore specied.

1. rl`l1e con1bination,with the pairof expan sion-pulleys, their belt, and their shai ts, ot' the shaft S, spindle Stand rotary screw S", Wormgearing connecting the same with the driven shaft and with each other, the traveling nut N, slotted lever L, movable fulcrum-arnrA,

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slide S', and coupling-bm' C, substantially :is liereinbefore specified.

5. The comhination, substantially as llore.- inbefore specified, of the handWl1eelH,shaft S3, spindle S4, rotary screw S5, Worm-gearing connecting said shaft, spindle, and screw, the traveling nut N, level'1 L, slide S', and coumeting-bai' C, for simultaneously reziljusting the expansion-pulleys by hand.

JOHN G. AVERY.

Witnesses:

E. B. ELDRIDGE, JOHN E. GODDARD. 

